Brown dye.



UltllTEU Tans PATENT OFF CE.

WILIIELM HERZBERG AND OTTOyHANSMANN, OF BERLIN, GERMANY, AS-

SIGNORS TO THE AOTIEN-GESELLSCIIAFT' FUR ANILIN FABRIKATION,

O F SAME PLACE.

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SijilEGIFIOATION forming part of Letters Patent No. 657,064, dated August 28, 1900.

Application filed June 28. 1900; Serial No. 21,9 86. (Specimens) '1) mi] Ink/mt 7'! may concern:

Be it known that we, WILHELM Hnnznnnc It is well known that forcertain dyeing purposes it is necessary that the dyestuffs used should dye very uniformly and resist at the same time milling, soaping, &c. As a rule the power to dye uniformly of coloring-matters depends-upon a certain degree of solubility. On the other hand, increasing solubility in most cases is accompanied by a diminished fastness to milling and soaping.

Hence it is of greattechnical importance to produce dyestuffs which possess both the valuable properties above referred to. Mordant-dyeing coloring-matters of an extraordinary fastness to milling are obtained by combining diazotized picramic acid with meta; diamins. (Compare German Patent No. 112,819 of illarch a,1898,granted to the Action- Gesellschaft furAuilin Fabrikation.) In order to impart to them a greater power to dye 3o uniformly, the next way would be to increase their solubility by the introduction of acid radicals. However, the coloring-matters produced, for instance, by combining the diazo compound of picramic acid with meta-diamin- 5 sulfonic acids proved to be considerably less fast to milliu We have now made the unex- D I pected discovery that by starting from chlorometa-phenyleuediamin (Cl :NH :NH 1 :2 :4)

a coloring-matter is obtained, the solubility 40 and power to dye uniformly of which is superior to those of the dyestuffs of German Patent No. 112,819, while its fastness to milling, soaping, do, remains unchanged. Most probably in this case the chlorin atom acts as a weakly acid group, preventing the salt of the dyestuft from being dissociated.

Our new dyestuffis extraordinarily fit for all purposes for which combined fastness and power to dye uniformly are required. It is the more valuable as chloro-meta-phenylenediamin, (Ol:NH :NI I :1:2:4,) is easily obtainable, and a product of but little cost.

Tofurther illustrate our invention, we give the following directions: 22. 1 kilos of sodium picramate are dissolved in water and twenty kilos of concentrated hydrochloric acid, (specific gravity equals 1.16.) The solution obtained is diazotized by means of 6.0 kilos of sodium nitrite. to run slowly into asolution of 11.5 kilos of chlorophenylenediamiu (Cl: N11 GIL: 1 2: 4:) andthe mixture is well stirred during several hours. 5.3 kilos of sodium carbonate are then added thereto. The liquid is heated. andthe dyestuif is precipitated by means Of'COlH- mon salt. The sodium salt of the dyestulf thus obtained is soluble in water with yel lowish-red coloration, which on addition of sodium carbonate or caustic-soda lye turns slightly more yellowish. From this aqueous solution the dyestuff separates on addition of acetic acid in the form of a dark-red precipitate. It is hardly soluble in alcohol with yellowish-red coloration. It dissolves in concentrated sulfuric acid, forming a magentared solution, which on addition of ice water turns yellowish and on continued dilution separates.brownish-yellow flakes.

The dyestufi dyes chromium-mordantcd wool fine brown shades of great-intensity and of an extraordinary fast'ness to milling and to light.

The diazo solution is allowed Having now described our invention and p in what manner the same is to be performed, what we claim as new is- The brown dye produced by combining di azotized picramic acid with chloro-meta-phenylenediamin (ClzNl-l zNll lflztz); the sodium salt of the dye being soluble in water with yellowish-red coloration which on addition of sodium carbonate or caustic-soda lye turns slightly more yellowish; the dye being precipitated from this aqueous solution by means of acetic acid in the form of a darkred powder; the dye being hardly soluble in alcohol with yellowish rcd coloration; easily soluble in concentrated sulfuric acid forming a magenta-red solution which on addition 01' ic-watr tu'r'ils yellowisb an d bn continued our marries, this 14th day of June, 1900, in the dilution separates brownish-yellow fiakes presence of two subscribing witnesses. ,the dye'producingon chromium-mol dante'd VVI'LHELM HERZBERG. wool fine brown shades of great intensity and OTTO H-ANSMANN. 5 of an extraordinary fastness to milling-aim Witnesesa I to light. 1 HENRY HASPER,

In wit-nss wherieof we have hereunto signed WOLD'EMAR -HAUPT. 

